A total of 538
female specimens of the greater lizardfish, Saurida tumbil, were collected from the Persian Gulf,
Bushehr Province, from Feb 2007 to Feb 2008. Mean absolute and relative
fecundity was calculated as 263162+31046 and 273+27, respectively. The minimum
and maximum ova diameter was 6|i (stage 1) and 875^ (stage 5) with a mean+SD of
318+62 ^. The curvilinear relationship between the fecundity and total weight
of the fish was F=2657.8 W a6617.

Introduction

The greater
lizardfish, Saurida
tumbil, is a member of
the family Synodonthidae and are common and widely distributed through Indian
and Pacific waters, the Oman and Arabian seas and the Persian Gulf and it is
commercially important for the local fishery.

The greater
lizardfish inhabits sandy, muddy or coral reefs from the coastal line to depth
of 100m. Greater lizardfish is most abundant species in both number and weight
found in demersal fish assemblages in the Persian Gulf. In Bushehr Province, it
is taken by many fishing methods, including bottom trawl and gill nets,
however, its abundance has decreased steadily in the recent years in the world
(Froese and Pauly, 2012). Ecological factors affect the biological and
reproductive characteristics of fish population, and so these kinds of
investigations

should be carried
out periodically and determining the reproductive biology of a species within
its native range is necessary for management purposes. The main purpose of the
present investigation was to study reproduction biology of S. tumbil, including fecundity and egg diameter
variations in Bushehr Province, in south of Iran.

Materials
and methods

The study was
carried out on a S.
tumbil population in
the Persian Gulf. Monthly collections were made from February 2007 to February
2008, where a total of 538 female S. tumbil specimens
were collected from commercial fishing boats in Bushehr Province, Iran. These
specimens were caught by gillnet and trawls during the early morning hours and
brought to the laboratory fresh on ice. Total length (TL) and body weight (BW)
were recorded from the specimens to the nearest 1 mm and to the nearest 1 g,
respectively. The gonads were dissected from the fish and weighted to the
nearest 0.01 g (GW) while the sex was determined by visual inspection.
Fecundity was estimated by using wet weight technique. After weighing the
ovaries, 3-5 subsamples of known weight were extracted from different parts of
the ovary lobe and each subsample weighed to the nearest 0.001 g and then
counted.

Results

The length frequency
of S. tumbil specimens collected in this study is shown
in Fig.1. The most abundant group of females belonged to the 43.1­48 cm. Mean
absolute and relative fecundity was 263162 + 31046 and 273 + 27, respectively.
The minimum and maximum ova diameter was 6| (stage 1) and 875^ (stage 5) with a
mean of 318+62 ^. The curvilinear relationship between the fecundity and total
weight of the fish was

F=2657.8 W 0.6617
(Fig. 2). The first year maturity size (TL) for females

was 27 cm. Ovaries
contained oocytes at various stages of development. Oocyte development of
greater lizardfish collected along the northern coast of the Persian Gulf was
consistent with batch spawning that exhibit synchronous development. Females at
maturity stages III -V were mature.

Information
regarding the reproductive biology of the S. tumbil species in Persian Gulf is quite limited
and the sample size of previous studies were inadequate. In the present study,
we elucidated the fecundity and egg diameter variation of greater lizardfish in
this area. Fecundity varied from a mean of 140742 + 8541 eggs per female at
weight 399 g to a mean of 456985 + 24218 eggs per female at weight 1470 g. This
was correlated significantly with fish weight, body length, age and gonad
weight, and it is increased as gonad weight and fish length increased. Soofiani
et al. (2006) showed that the number of eggs in this fish ranged between 74444
and 250452 in a nearby population.

One of the most
important parameters used to define reproductive potential is the variation of
egg diameter in the ovaries. The minimum and maximum ova diameter was
correlated with fish weight, length and gonad weight. Egg diameter may be
related to the amount of food that females can metabolize (Nikolsky, 1963).
During the year, different combinations of oocyte types were seen within the
ovary. Fully grown and mature oocytes were detected in May and October. These
results are in line with other studies (Budnichenko & Nor, 1978; Soofiani
et al., 2006; Budnichenko, 1974).

Morphologically, the
attack of follicular atresia is revealed by hypertrophy of the granulose layer,
followed by digestion of the vitelline envelope, split of the cytoplasmic
cortex, and nuclear membrane decomposition (early atresia). Then it is followed
by rapid phagocytosis of the oocyte yolk (inter -mediate atresia) and formation
of the atretic body attacked by the transformed follicular and blood-borne
cells with a capillary infiltration (late atresia). During the spawning season
postovulatory follicles were observed together with oocytes at yolk stage in
ovaries of greater lizardfish as well as another close lizardfish species
(Budnichenkoo and Dimitrova, 1979). We believe that our study provides some
important information on the reproductive biology of S. tumbil that will be helpful in similar studies.

Fig. 2. Relationship
between the fecundity and total weight in S. tumbil

A total of 538
female specimens of the greater lizardfish, Saurida tumbil, were collected from the Persian Gulf,
Bushehr Province, from February 2007 to February 2008. Mean absolute and
relative fecundity was calculated as 263162+31046 and 273+27, respectively. The
minimum and maximum ova diameter was 6|i (stage 1) and 875|i (stage 5) with a
mean+SD of 318+62 |i. The curvilinear relationship between the fecundity and
total weight of the fish was F=2657.8 W °'6617.

The greater
lizardfish, Saurida
tumbil, is a member of
the family Synodonthidae and are common and widely distributed through Indian
and Pacific waters, the Oman and Arabian seas and the Persian Gulf and it is
commercially important for the local fishery. The greater lizardfish inhabits
sandy, muddy or coral reefs from the coastal line to depth of 100m. Greater
lizardfish is most abundant species in both number and weight found in demersal
fish assemblages in the Persian Gulf. In Bushehr Province, it is taken by many
fishing methods, including bottom trawl and gill nets, however, its abundance
has decreased steadily in the recent years in the world (Froese and Pauly,
2012). Ecological factors

affect the
biological and reproductive characteristics of fish population, and so these
kinds of investigations should be carried out periodically and determining the
reproductive biology of a species within its native range is necessary for
management purposes. The main purpose of the present investigation was to study
reproduction biology of S. tumbil, including
fecundity and egg diameter variations in Bushehr Province, in south of Iran.

Materials
and methods

The study was
carried out on a S.
tumbil population in
the Persian Gulf. Monthly collections were made from February 2007 to February
2008, where a total of 538 female S. tumbil specimens
were collected from commercial fishing boats in Bushehr Province, Iran. These
specimens were caught by gillnet and trawls during the early morning hours and
brought to the laboratory fresh on ice. Total length (TL) and body weight (BW)
were recorded from the specimens to the nearest 1 mm and to the nearest 1 g,
respectively. The gonads were dissected from the fish and weighted to the
nearest 0.01 g (GW) while the sex was determined by visual inspection.
Fecundity was estimated by using wet weight technique. After weighing the
ovaries, 3-5 subsamples of known weight were extracted from different parts of
the ovary lobe and each subsample weighed to the nearest 0.001 g and then
counted.

Results

The length frequency
of S. tumbil female specimens collected in this study is
shown in Fig.1. The most abundant group of females belonged to the 33.1-38 cm.
Mean absolute and relative fecundity was 263162+31046 and 273+27, respectively.
The minimum and maximum ova diameter was 6|i (stage 1) and 875|i (stage 5) with
a mean of 318+62^. The curvilinear relationship between the fecundity and total
weight of the fish was

F=2657.8 W 0.6617
(Fig. 2). The first year maturity size (TL) for females

was 27 cm. Ovaries
contained oocytes at various stages of development. Oocyte development of
greater lizardfish collected along the northern

coast of the Persian
Gulf was consistent with batch spawning that exhibit synchronous development.

Fig. 1. Length
frequency of S. tumbil females.

Fig. 2. Relationship
between the fecundity and total weight in S. tumbil.

Discussions
and Conclusions

Information
regarding the reproductive biology of the S.
tumbil species in Persian Gulf is quite limited
and the sample size of previous studies were inadequate. In the present study,
we elucidated the fecundity and egg diameter variation of greater lizardfish in
this area. Fecundity varied from a mean of 140742 ± 8541 eggs per female at
weight 399 g to a mean of 456985 ± 24218 eggs per female at weight 1470 g. This
was correlated significantly with fish weight, body length, age and gonad
weight, and it is increased as gonad weight and fish length increased. Soofiani
et al. (2006) showed that the number of eggs in this fish ranged between 74444
and 250452 in a nearby population.

One of the most
important parameters used to define reproductive potential is the variation of
egg diameter in the ovaries. The minimum and maximum ova diameter was
correlated with fish weight, length and gonad weight. Egg diameter may be
related to the amount of food that females can metabolize (Nikolsky, 1963).
During the year, different combinations of oocyte types were seen within the
ovary. Fully grown and mature oocytes were detected in May and October. These
results are in line with other studies (Budnichenko and Nor, 1978; Soofiani et
al.,

2006).

Morphologically, the
attack of follicular atresia is revealed by hypertrophy of the granulose layer,
followed by digestion of the vitelline envelope, split of the cytoplasmic
cortex, and nuclear membrane decomposition (early atresia). Then it is followed
by rapid phagocytosis of the oocyte yolk (inter -mediate atresia) and formation
of the atretic body attacked by the transformed follicular and blood-borne
cells with a capillary infiltration (late atresia). During the spawning season
postovulatory follicles were observed together with oocytes at yolk stage in
ovaries of greater lizardfish as well as another close lizardfish species
(Budnichenko and Dimitrova, 1979).

Acknowlegements

We would like to
thank all the people helped us during the field work and fish sampling. This
study was financially supported by Iran Fisheries Research Organization,
Isfahan University of Technology and Persian Gulf University of Bushehr.

Saprolegniasis is a
serious mycotic winter freshwater fish disease, often affects wild and cultured
fishes (Hussien et al, 2010) and is responsible for fungl infections and
mortalities of fish and eggs. In hatcheries, infection usually begins in
unfertilized eggs and spreads to live eggs which decrease the production (Noga,
2000). Sometimes, mortality rate by saprolegniasis in Acipenser persicus eggs during incubation has reached to 70 -
90% (Bauer et al, 2002). There are some chemical antifungal agents that are
used to reduce saprolegniasis in hatcheries including formalin (Scherier,
1996), hydrogen proxide (Rach et al 2003),
malachite green (Alderman, 1985) and etc. factors like health status of agents
for human and environment, their ecological impacts, and long term effects to
fish physiology, are very important points to choose them as antifungal agents.
For example malachite green and formalin represented as low withdrawal affinity
and high carcinogenic activity on human and fish (Osman et al, 2008). During
the last decade, numerous aquatic bacteria have been found to be antagonistic
to well-known aquatic bacteria pathogens (Lategan et al., 2004). Reports on the antifungal properties
of bacteria have been centered mostly on the biocontrol of fungal
Phytopathogens (Verschuere et al., 2000
and Gastwright et al., 1995). Antifungal activity against
pathogenic Oomycetes has been tested in the genera Pseudomonas fluorescens (Bly, 1997 and Ahmadzadeh ,2006 ) Pseudomonas sp. (Adams, 2002), Aeromonas sp. (Hussein & Hataii, 2001;Osman et al., 2008 and Hussein

The present study
was designed to investigate potential biological agent for biocontrol of
saprolegniasis in persian sturgeon eggs (Acipenser persicus) by Pseudomonase
aeroginosa (PTCC1430)
in sturgeon hatcheries.

Material
and Methods

Preparation of P.
aeroginosa PTCC1430

This strain was
obtained originally from Persian Type Culture Collection, PTCC1430. Then it was
grown in PDB (Potato Dextrose Broth) media. After centrifugation (1038 g) at 4
C for 10 min, bacteria sediment was separated from the media. Confidently, the
sediment centrifuged three times. Afterwards, PBS (5 C) was added with the
latest sediment and then shaked well with rotary shaker set. This liquid
absorbance was read at 600 (nm) using a spectrophotometer (Gopalakannan and
Arul, 2011).

The basic media was
inoculated by bacterial concentration of 107 cfu. ml-1.
The next treating concentrations (106,105cfu.ml-1)
were prepared from this main bacterial solution.

Challenge design

Challenge design was
carried out in Shahid Marjany Sturgeon Fish Center, Golestan province and
preparation of P.
aeroginosa was done in
the Caspian Sea Eecology Research Institute, Mazandaran Province.

Green eggs from
Persian Sturgeon (Acipenser
persicus) were placed
in Yushchenco Incubator trays. The thirty-hour eggs were confined within
Nylonic cages (15x15x10 cm; 50 eggs per cage) (Abtahi et al 1994). During incubation and treating
stages, water flow was about 2.5 l/min. Three cages were used as replicates for
each treatment level and three cages used for control. Fish eggs were treated
by three duration times (15, 30 and 45 min), three concentration levels of
bacterial bath (105, 106 and 107 cfu. ml-1)
and two times (once at first incubation day

and three times
during the incubation period). Infected eggs were assessed, counted and picked
up from cages daily.

Results
and Discussion

As indicated in the
table, there is only a significant effect of concentration (p< 0.01) while
no significant effects of duration and times were found on egg fungal infection
(p> 0.05). There is a significant interaction effect by times and bacterial
concentration and also a significant interaction effect by all three studied
factors (p< 0.05).

Regarding to the
figure, there are significant differences between 13 treats and control
(p<0.05). There were no significant differences between 4 treats of 107
cfu. ml-1concentration level and the control. The best effects were
belonged to 105 x 30 min x1time and 105 x15min x3 times
that reduce the fungal infections to 15% (as compared to the control with 44%
egg fungal infection).

The ability of
bacteria to inhibit saprolegnia infection might be implicated to its ability to
liquefy gelatin of such fungi (Holt et al, 1993). Another candidate for the
inhibitory activity for saprolegnia is cellulose (Hussein and Hatai, 2001). Bly
(1996) reported that inhibition of saprolegnia by bacteria not related to the
secretory substance but rather the result of competition (Bly et al, 1996) (Bly
et al, 1997). In the present study, with increasing the concentration of
bacteria, the effect of bacteria to control of fungal infections was reduced
that could be related to extra cellular enzymes that might damage the egg
membrane.

Acknowledgement

The authors are
grateful of all colloquies of Shahid Marjani Sturgeon Fish Centre, The Caspian
Ecology Research Centre and Golestan Fish Organization.

100

90 80 70 60 50

i 40 30
20

10 0

. 20

25.3

cd15;3cd 16

dt d

rill

41.3

29.32433-32H8.627 6ab 32-729.3
2420.7bcdcd abcbcdbcdbcd T abc bcd

cd cd
. _ T 1 , . H T

40.7 ab

45

1

1

I

25.3 cd

43.8 a

a

Treatment

Table: Analysis of
variance of the effect of concentration, duration and times of bacterial
treatments on fungal infections of Persian sturgeon eggs.

Sig.

F

Mean Square

df

Sum of Square

Source

0.00

**21.275

1444.222

2

2888.444

concentration

0.96

0.04

2.741

2

5.481

duration

0.718

0.131

8.914

1

8.914

times

0.67

0.592

40.185

4

160.741

Con. x dur.

0.015

*4.49

304.765

2

609.531

Con. x times

0.024

*3.944

267.728

2

535.457

Dur. x times

0.233

1.436

97.469

4

389.877

Con. x dur. x times

67.884

63

4276.667

Error

80

10263.802

Total

*. Shows significant
difference at the level of 0.05 ** shows significant difference at the level of
0.01

Hussien, A. M.
Osman. Ahmad, I. E. Noor El Deen. Waled, S.E. Saman. 2010. A trial for I
nduction of saprolegniasis in Mugil cephalus with special reference to biological control .Journal of American
Science.6(6).203

Several factors
affect egg and fry quality in fish species. These are either endogenous:
genotype, age and size of broodstock, ovarian

characteristics, egg
size and gamete age (Carillo et al. 2000) or exogenous: bacterial colonisation
of egg surface, egg management, broodstock feeding (Bromage and Roberts 1995).
In particular, reproductive performance is deeply affected by the nutritional
status of fish, which is known to condition several reproductive traits, such
as age at maturity, fecundity, egg size, chemical composition of eggs and also
embryonic development (Carillo et al. 2000). In freshwater fish, embryonic
development depends on the energetic reserves of the yolk sac. This is
particularly true for Salmonids, as their embryonic structures are highly
developed and their trophic function lasts for many days after hatching.
Previous research demonstrated that changes in yolk composition, through diet
and feeding levels, could also affect fry survival (Knox et al. 1988). Among
dietary components a primary role is played by energy. In fact net energy
requirements for maintenance are to be satisfied before growth and reproduction
(Cho and Kaushik 1990). These authors, and others (Da Silva and Anderson 1995),
pointed out that energy may be diverted from somatic growth when energy
requirements for reproduction increase at the end of gonadal development.
Maternal nutrition is the only source of fatty acids until the beginning of
exogenous feeding. Watanabe et al. (1984) observed that lipid sources in
broodstock diets affect egg quality, their hatching rate, also demonstrating
that a dietary fatty acid deficiency could cause a decrease in gamete numbers
and a high mortality of embryos. On the other hand, broodstock diets rich in
polyunsaturated fatty acids (PUFA) increase the risks of eggs being exposed to
peroxidation and tissue damage. As a consequence, PUFA level and the presence
of antioxidant substances in the gamete are strictly related to egg quality
(Pickova et al. 1999). The aim of this study was to evaluate the effects of two
isolipidic and isoproteic diets, through the progressive replacement of fish
oils (i.e., polyunsaturated fatty acids), with dietary blend vegetable oil
(i.e., saturated fatty acids), on reproductive traits of rainbow trout.

Thirty six rainbow
trout 4 year old broodstocks were stocked twelve (6 females/6 male) in 6
polyethylene tanks (1000 L) supplied with freshwater at a flow rate of 15 L min-1.
Light/dark cycle was 8 L:16 D. Water quality parameters were monitored daily
for each tank and pH, temperature and dissolved oxygen were maintained at
7.3-7.7, 14-15°C and 7.5-8.4 mg L-1, respectively. Two experimental
diets with similar protein, lipid and energy content were formulated to contain
blend vegetable oil sources to replace fish oil (Table 1). Kilka (Clupeonella sp.) meal and oil (Kilkapodre-sahar, Co,
Iran) was the primary sources of fish meal and oil in the control and the
experimental vegetable oil source was a mixture of canola: linseed: safflower
oil (40:30:30, respectively). Table 2 shows the formulation and proximate
composition of the experimental diets.

Three months after
feeding (3 weeks before the full maturation of females), males and females were
separated and each transferred to separate tanks. Fish were not fed after
separate and checked for ripeness during the expected ovulation period weekly.
To checking ovulation, fish were anaesthetized with 200 mg L-1 of
clove solution before handling. Ovulated females, were separated and
non-ovulated fish were returned to the tanks. Weight and total length of fish
were measured. Gametes were collected and Pooled sperm were added. Then the
gametes were gently mixed (2-3 min). Water was added to the gametes which were
mixed, then rinsed ( 10-20 min ) and held for an additional 45 min for
water-hardening . Eggs of each female were incubated in flow-through systems in
incubation trays (with dimensions of 42.5 cm x 42.5 cm x 20 cm) randomly. Eggs
of individual females were incubated and hatched separately. well water
supplied at a flow rate of 9 L min-1 per 1kg of water-hardening eggs
. All treatments were subjected to 2ppm formalin daily to prevent fungus
infection.